A/C compressor shot?

[Zeppelin]

I've been reading up on everybody's A/C problems, but haven't really caught a scenario that I'm in.. I had my engine replaced almost a year ago, and the A/C hasn't worked since. I checked under the hood during the winter and noticed the belt was gone. I finally got around to putting one on today, but the A/C still doesn't work.. I can get the compressor to turn somewhat easily with a socket wrench, but it won't spin under its own power.... I also believe that I need to get the system recharged. Would not having any R-134a in the system keep the compressor from turning? I plan on getting the R-134a filled soon (within the next week or so), so I guess I'll find out then.. Just hoping someone can ease my tensions